Police and Crown Prosecution Service disclosure failings outlined in a new report increase the risks of miscarriages of justice occurring in criminal cases, according to the Centre for Criminal Appeals.

The CPS Inspectorate report’s findings also underpin the need for greater access to police files following a conviction in order to ensure unsafe convictions can be corrected, according to the Centre.

The report, published yesterday, found that in 40.7% cases, police did not fully meeting their disclosure obligations – up from 38.5% in 2015.

In criminal cases, the law requires that the CPS to hand over to the defence any material that may undermine the prosecution case or assist the defence case. The study found that in only 56.9% of cases prosecutors fully complied with this ongoing duty. Where sufficient disclosure does not happen, miscarriages of justice can result.

The main police disclosure failings uncovered by the report included the police failing to reveal the previous convictions of witnesses, an issue discovered in 10.1% of cases.

Other disclosure failings including the police listing items gathered during the course of their investigation wrongly, providing poor descriptions of them, or failing to provide a list of such material altogether.

“The disclosure failings exposed by this report are deeply concerning to anyone who rightly expects our justice system to ensure innocent people aren’t wrongly imprisoned.

“The report also shows the need for greater transparency from the police and CPS. We frequently find our ability to investigate miscarriage of justice cases is hampered by not being able to access their documents even after conviction.

“In much of the United States, police files and prosecutor files on a case become a matter of public record once a conviction is made. In England and Wales we are far less transparent – and it is miscarriage of justice victims who lose out as they are prevented from being able to prove their innocence.”